/////////////////////////////////////////////////////////////////////////////
// Original code from libhdfs3. Copyright (c) 2013 - 2014, Pivotal Inc.
// All rights reserved. Author: Zhanwei Wang
/////////////////////////////////////////////////////////////////////////////
//  Modifications by Kumo Inc.
// Copyright (C) Kumo inc. and its affiliates.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//



#include <kmhdfs/client/user_info.h>

#include <pwd.h>
#include <sys/types.h>
#include <unistd.h>

#include <vector>

#include <kmhdfs/common/exception.h>
#include <kmhdfs/common/exception_internal.h>

namespace Hdfs {
namespace Internal {

UserInfo UserInfo::LocalUser() {
    UserInfo retval;
    uid_t uid, euid;
    int bufsize;
    struct passwd pwd, epwd, *result = NULL;
    euid = geteuid();
    uid = getuid();

    if ((bufsize = sysconf(_SC_GETPW_R_SIZE_MAX)) == -1) {
        THROW(InvalidParameter,
              "Invalid input: \"sysconf\" function failed to get the configure with key \"_SC_GETPW_R_SIZE_MAX\".");
    }

    std::vector<char> buffer(bufsize);

    if (getpwuid_r(euid, &epwd, buffer.data(), bufsize, &result) != 0 || !result) {
        THROW(InvalidParameter,
              "Invalid input: effective user name cannot be found with UID %u.",
              euid);
    }

    retval.setEffectiveUser(epwd.pw_name);

    if (getpwuid_r(uid, &pwd, buffer.data(), bufsize, &result) != 0 || !result) {
        THROW(InvalidParameter,
              "Invalid input: real user name cannot be found with UID %u.",
              uid);
    }

    retval.setRealUser(pwd.pw_name);
    return retval;
}

size_t UserInfo::hash_value() const {
    size_t values[] = { StringHasher(realUser), effectiveUser.hash_value() };
    return CombineHasher(values, sizeof(values) / sizeof(values[0]));
}

}
}
